证明:求l(x):门次多项式,满足条件 0=l(x0)=l1(x1) 0i≠j 如l(x)满足证明：求 ( ) j l x ：n 次多项式，满足条件 { 0 1 1 1 0 ( ) ( ) ( ) ( ) ( ) 1 ( ) j j j j j j j n j j l x l x l x l x l x l x = = =  = = =  = − + = 即 0 { 1 ( ) j i i j i j l x  = = 如 0 l x( )满足0 1 0 2 0 ( ) ( ) ( ) 0 n l x l x l x = =  = =